#define _CRT_SECURE_NO_WARNINGS  1
#include<stdio.h>
int ret_2(int a)
{
	int count = 0;
	while (a)
	{
		a /= 2;
		count++;
	}
	return count;
}
int main()
{
	int a = 15;
	printf("%d",ret_2(a));
	return 0;
}